Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Some facts about Deep Thought / Deep Blue

Author: Gian-Carlo Pascutto

Date: 02:28:14 08/30/01

Go up one level in this thread


On August 29, 2001 at 23:10:56, Robert Hyatt wrote:

>The "weights" don't always reveal what they stand for.  I've had the DT
>code for at least 2 years.  It isn't new.  But I can give you the weights I
>use in Crafty and they don't tell you _what_ I am actually doing with them,
>only the numbers I am using.  Their bishop of opposite color + pawn ending
>evaluation was _very_ good.  Once Hsu explained it to me at an ACM event.
>You won't find that explanation of how it works in the stuff you reference.
>
>Which is a shame, actually.  There's a lot in the thing that we won't ever
>know in great detail.

The code includes the full eval itself. You can check it out and see
how they did kingsafety, bad bishops, passed and blocked pawns, etc...

The tuner has that code because it is useless without it. You can't
tune an eval if you haven't got any.

What I don't see is the endgame stuff you talk about. I see two possible
explanations:

a) they thought it was so great that it shouldnt leak out and carefully
removed all references from it from the tuner

b) they simply didnt _have_ it yet at the 1988 US Open. Perhaps it was
added afterwards in DT, DT2 or DB, and you are confused about when they
talked about it to you or implemented it.

Make your pick.

I think what the code shows is that in the 1988 US Open, Deep Thought
did not have great sophisticated evaluation. An ok one yes, but it's
certainly been surpassed by the micros in the meantime.

Which doesn't mean anything about the evaluation of DT after 1988 or
of its succesors, but I find it awkward to be making much fuss about
DT's supposed evaluation if you can _look_ at it and see what they
did and did not do.

--
GCP



This page took 0.01 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.